1
JEE Main 2015 (Offline)
MCQ (Single Correct Answer)
+4
-1
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When $$5V$$ potential difference is applied across a wire of length $$0.1$$ $$m,$$ the drift speed of electrons is $$2.5 \times {10^{ - 4}}\,\,m{s^{ - 1}}.$$ If the electron density in the wire is $$8 \times {10^{28}}\,\,{m^{ - 3}},$$ the resistivity of the material is close to :
A
$$1.6 \times {10^{ - 6}}\Omega m$$
B
$$1.6 \times {10^{ - 5}}\Omega m$$
C
$$1.6 \times {10^{ - 8}}\Omega m$$
D
$$1.6 \times {10^{ - 7}}\Omega m$$
2
JEE Main 2014 (Offline)
MCQ (Single Correct Answer)
+4
-1
In a large building, three are $$15$$ bulbs of $$40$$ $$W$$, $$5$$ bulbs of $$100$$ $$W$$, $$5$$ fans of $$80$$ $$W$$ and $$1$$ heater of $$1$$ $$kW.$$ The voltage of electric mains is $$220$$ $$V.$$ The minimum capacity of the main fuse of the building will be:
A
$$8$$ $$A$$
B
$$10$$ $$A$$
C
$$12$$ $$A$$
D
$$14$$ $$A$$
3
JEE Main 2013 (Offline)
MCQ (Single Correct Answer)
+4
-1
The supply voltage to room is $$120V.$$ The resistance of the lead wires is $$6\Omega $$. A $$60$$ $$W$$ bulb is already switched on. What is the decrease of voltage across the bulb, when a $$240$$ $$W$$ heater is switched on in parallel to the bulb?
A
zero
B
$$2.9$$ Volt
C
$$13.3$$ Volt
D
$$10.04$$ Volt
4
JEE Main 2013 (Offline)
MCQ (Single Correct Answer)
+4
-1
This questions has Statement - $${\rm I}$$ and Statement - $${\rm I}$$$${\rm I}$$. Of the four choices given after the Statements, choose the one that best describes into two Statements.

Statement - $${\rm I}$$ : Higher the range, greater is the resistance of ammeter.
Statement - $${\rm I}$$$${\rm I}$$ : To increase the range of ammeter, additional shunt needs to be used across it.

A
Statement - $${\rm I}$$ is true, Statement - $${\rm II}$$ is true, Statement - $${\rm II}$$ is the correct explanation of statement - $${\rm I}$$.
B
Statement - $${\rm I}$$ is true, Statement - $${\rm II}$$ is true, Statement - $${\rm II}$$ is not the correct explanation of statement - $${\rm I}$$.
C
Statement - $${\rm I}$$ is true, Statement - $${\rm II}$$ is false
D
Statement - $${\rm I}$$ is false, Statement - $${\rm II}$$ is true
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